Measurement properties of the incremental step test for people with chronic obstructive pulmonary disease: a cross-sectional study

OBJECTIVES

The new incremental step test (IST) is a field test that was developed for people with chronic obstructive pulmonary disease (COPD), based on the characteristics of the incremental shuttle walk test (ISWT); however, its measurement properties still need to be determined. We aimed, first, to assess the construct validity (through the comparison with the ISWT), within-day reliability and measurement error of the IST in people with COPD; and, second, to identify whether the participants have a learning effect in the IST.

DESIGN

Cross-sectional study, conducted according to COnsensus-based Standards for the selection of health status Measurement INstruments guidelines.

SETTING

A family health unit in Portugal, April 2022 to June 2023.

PARTICIPANTS AND ANALYSIS

63 participants (67.5±10.5 years) attended two sessions to perform two IST and two ISWT, separately. Spearman's correlations were used to compare the best performances between the IST and the ISWT. Intraclass correlation coefficient (ICC2,1) was used for reliability, and the SE of measurement (SEM), minimal detectable change at 95% CI (MDC95) and Bland and Altman 95% limits of agreement (LoA) were used for measurement error. The learning effect was explored with the Wilcoxon signed-rank test.

RESULTS

The IST was significant and strongly correlated with the ISWT (0.72<ρ<0.74, p<0.001), presented an ICC2,1 of 0.95 (95% CI 0.92 to 0.97), SEM=11.7 (18.9%), MDC95=32.4 (52.2%) and the LoA were -33.61 to 31.48 for the number of steps. No difference was observed between the number of steps of the two attempts of the IST (p>0.05).

CONCLUSIONS

The IST can be suggested as a valid and reliable test to assess exercise capacity in people with COPD, with no learning effect when two IST are performed on the same day. The measurement error of the IST is considered indeterminate.

TRIAL REGISTRATION NUMBER

NCT04715659.

Long-Term Electrode-Skin Impedance Variation for Electromyographic Measurements

This study aims to observe the evolution of the electrode-skin interface impedance of surface EMG electrodes over the time taken to determine the time of stabilization. Eight healthy subjects participated in the study. Electrode-skin impedance was evaluated in the rectus abdominal muscle every five minutes, over a total period of 50 min. A reduction of 13.23% in the impedance values was observed in minute 10 (p = 0.007), and a reduction of 9.02% was observed in minute 15 (p = 0.029). No statistically significant differences were observed in the other instants evaluated. The findings obtained in the present study demonstrate a decrease in electrode-skin impedance from minute 5 to minute 15, followed by a stabilization period with a low percentage of variation till minute 50.

Laboratory Studies about Microplastic Aging and Its Effects on the Adsorption of Chlorpyrifos

The constant change in microplastics (MP) due to exposure to environmental conditions leads to physical and chemical changes that enhance their ability to transport other pollutants, increasing the concern about their widespread presence in the environment. This work aimed to simulate the aging process of six MP (polyamide 6, unplasticized polyvinyl chloride, low-density polyethylene, polystyrene, polyethylene-co-vinyl acetate, polypropylene) in freshwater and seawater ecosystems at laboratory scale and evaluate its effects through optical microscope observation, Fourier transform infrared spectroscopy-Attenuated Total Reflectance (FTIR-ATR), Raman spectroscopy, and thermal gravimetric analysis (TGA). Through a combined experimental study of aged MP, the degradation by UV interaction was evidenced by the appearance of new infrared bands in the FTIR spectra assigned to ketones and hydroxyl groups. While Raman analysis and microscope images reveal the appearance of pores, wrinkles, and roughness in the MP surfaces. Variations in the temperature of the maximum weight loss of the MP were observed in the TGA analysis. The adsorption of chlorpyrifos (CPF), a common pesticide widely used in agriculture, by the pristine and aged MP was also studied. The highest affinity for CPF was observed for pristine LDPE and the lowest for PP. The batch adsorption studies revealed an increase in adsorption capacity as a consequence of the aging process for both MP. These results proved that the weathering effects caused changes in the behavior of MP, namely in the interaction with other pollutants.

Reference Equation of a New Incremental Step Test to Assess Exercise Capacity in the Portuguese Adult Population

Step tests are important in community- and home-based rehabilitation programs to assess patients' exercise capacity. A new incremental step test was developed for this purpose, but its clinical interpretability is currently limited. This study aimed to establish a reference equation for this new incremental step test (IST) for the Portuguese adult population. A cross-sectional study was conducted on people without disabilities. Sociodemographic (age and sex), anthropometric (weight, height, and body mass index), smoking status, and physical activity (using the brief physical activity assessment tool) data were collected. Participants performed two repetitions of the IST and the best test was used to establish the reference equation with a forward stepwise multiple regression. An analysis comparing the results from the reference equation with the actual values was conducted with the Wilcoxon test. A total of 155 adult volunteers were recruited (60.6% female, 47.8 ± 19.7 years), and the reference equation was as follows: steps in IST = 475.52 - (4.68 × age years) + (30.5 × sex), where male = 1 and female = 0, and r² = 60%. No significant differences were observed between the values performed and those obtained by the equation (p = 0.984). The established equation demonstrated that age and sex were the determinant variables for the variability of the results.

Magnetostructural coupling in RFeO3 (R = Nd, Tb, Eu and Gd)

We investigate the interplay of magnetization and lattice vibrations in rare-earth orthoferrites RFeO₃, with a specific focus on non-symmetry-breaking anomalies. To do so, we study the magnetization, magnon excitations and lattice dynamics as a function of temperature in NdFeO₃, TbFeO₃, EuFeO₃ and GdFeO₃. The magnetization shows distinct temperature anomalous behavior for all investigated rare-earth orthoferrites, even in the compounds with no phase transitions occurring at those temperatures. Through spin-phonon coupling, these magnetic changes are mirrored by the FeO₆ rotation mode for all the studied RFeO₃, revealing a common magnetostructural effect associated with the octahedra rotations. The R³⁺ oscillation modes evidence a Fe³⁺/R³⁺ spins cross-talk for the NdFeO₃ and TbFeO₃ cases. Our work sheds light into the common magnetostructural coupling in rare-earth orthoferrites, and the important role of magnetic anisotropy and spin-orbit coupling strength of the R-Fe interactions on the spin-reorientation transition at high temperatures.

Effects of Abdominal Microcurrent in the Consumption and Proportion of Energy Substrates during Aerobic Exercise: A Pilot Study

Microcurrent therapy can increase lipolytic activity. However, it is unknown if the increased availability of lipids can influence the selection of energy substrates during a single session of aerobic exercise. We aimed to analyze the effect of microcurrent application to the abdominal region in the consumption of lipids and carbohydrates, and respiratory exchange ratio (RER) during a single session of moderate aerobic exercise in young adults. A pilot study was conducted in which participants were allocated to intervention (IG) or placebo (PG) groups. In both groups, 40 min of microcurrent application with two frequencies (25 and 10 Hz) followed by 50 min of moderate-intensity aerobic exercise (45−55% of heart rate reserve) on a cycloergometer were performed. The microcurrent application was performed without intensity in the PG. A portable gas analyzer (K4b2) was used during exercise in both groups. Thirty-eight participants (20.6 ± 1.8 years; 18 in IG and 20 in PG) were enrolled. There were no significant differences in the consumption of substrates or RER between the groups during exercise (p > 0.05). Microcurrent application seems to be insufficient to influence the consumption of energy substrates and RER during a single session of aerobic exercise in young adults.

The magnetic structure of DyFeO3revisited: Fe spin reorientation and Dy incommensurate magnetic order

High resolution and high intensity neutron powder diffraction is used to study the ground state magnetic order and the spin reorientation transition in the orthoferrite DyFeO₃. The transition from the high temperaturek= 0 Γ₄(G_xA_yF_z) to the low temperature Γ₁(A_xG_yC_z) type order of the Fe-sublattice is found atT_SR= 73 K and does not show any thermal hysteresis. BelowT_N2= 4 K the Dy-sublattice orders in an incommensurate magnetic structure withk= [0, 0, 0.028] while the Fe-sublattice keeps its commensurate Γ₁type order. DyFeO₃is the first orthoferriteRFeO₃to possess an incommensurate magnetic order of the rare earth sublattice under zero field conditions; an important piece of information neglected in the recent discussion of its multiferroic properties.

Validity and reliability of a new incremental step test for people with chronic obstructive pulmonary disease

BACKGROUND

Incremental step tests (IST) can be used to assess exercise capacity in people with chronic obstructive pulmonary disease (COPD). The development of a new step test based on the characteristics of the incremental shuttle walk test (ISWT) is an important study to explore. We aimed to develop a new IST based on the ISWT in people with COPD, and assess its validity (construct validity) and reliability, according to Consensus-based Standards for the selection of health status Measurement Instruments (COSMIN) recommendations.

METHODS

A cross-sectional study was conducted in participants recruited from hospitals/clinics. During the recruitment, the participants who presented a 6-minute walk test (6MWT) report in the previous month were also identified and the respective data was collected. Subsequently, participants attended two sessions at their homes. IST was conducted on the first visit, along with the 1 min sit-to-stand (1MSTS) test. IST was repeated on a second visit, performed 5-7 days after the first one. Spearman's correlations were used for construct validity, by comparing the IST with the 6MWT and the 1MSTS. Intraclass correlation coefficient (ICC_2,1), SE of measurement (SEM) and minimal detectable change at 95% CI (MDC95) were used for reliability. The learning effect was explored with the Wilcoxon signed-rank test.

RESULTS

50 participants (70.8±7.5 years) were enrolled. IST was significant and moderate correlated with the 6MWT (ρ=0.50, p=0.020), and with the 1MSTS (ρ=0.46, p=0.001). IST presented an ICC_2,1=0.96, SEM=10.1 (16.6%) and MDC95=27.9 (45.8%) for the number of steps. There was a statistically significant difference between the two attempts of the IST (p=0.030).

CONCLUSION

Despite the significant and moderate correlations with the 6MWT and 1MSTS, the inability to full compliance with the COSMIN recommendations does not yet allow the IST to be considered valid in people with COPD. On the other hand, the IST is a reliable test based on its high ICC, but a learning effect and an 'indeterminate' measurement error were shown.

TRIAL REGISTRATION NUMBER

NCT04715659.

Environmental diagnosis with Raman Spectroscopy applied to diatoms

Freshwater quality has been changing due to the ever greater use of water resources and the contamination load resulting from human activities. Management of these systems, thus, requires constant diagnose of water quality with fast and efficient methodologies. The conventional methods adopted are, however, time-consuming, often very expensive, and require specialised expertise. Raman spectroscopy (RS) is a simple, fast and label-free technique that can be applied to environmental diagnosis using diatoms. Here, we developed a diagnostic method based on Raman spectroscopy applied to freshwater diatoms. For this, Raman spectra were recorded from diatoms of three lakes of a natural city park. The data acquired was analysed by chemometrics methods to describe the data (Partial Least Squares Regression), infer relationships in the dataset (Cluster Analysis) and produce classification models (Artificial Neural Network). The classification models developed diagnosed the lakes with excellent accuracy (89%) without requiring taxonomic information about the diatom species recorded. This study provides a proof-of-concept for the application of diatom Raman spectroscopy to diagnosing water quality, laying an important foundation for future environmental studies aiming at assessing freshwater systems, to be replicated at larger scales and to varied geographic settings.

Raman spectroscopy applied to diatoms (microalgae, Bacillariophyta): Prospective use in the environmental diagnosis of freshwater ecosystems

Diatom species are good pollution bioindicators due to their large distribution, fast response to changes in environmental parameters and different tolerance ranges. These organisms are used in ecological water assessment all over the world using autoecological indices. Such assessments commonly rely on the taxonomic identification of diatom species-specific shape and frustule ornaments, from which cell counts, species richness and diversity indices can be estimated. Taxonomic identification is, however, time-consuming and requires years of expertise. Additionally, though the diatom autoecological indices are region-specific, they are often applied indiscriminately across regions. Raman spectroscopy is a simpler, fast and label-free technique that can be applied to environmental diagnosis with diatoms. However, this approach has been poorly explored. This work reviews Raman spectroscopy studies involving the structure, location and conformation of diatom cell components and their variation under different conditions. A critical appreciation of the pros and cons of its application to environmental diagnosis is also given. This knowledge provides a strong foundation for the development of environmental protocols using Raman spectroscopy in diatoms. Our work aims at stimulating further research on the application of Raman spectroscopy as a tool to assess physiological changes and water quality under a changing climate.

Strain relaxation dynamics of multiferroic orthorhombic manganites

Resonant ultrasound spectroscopy has been used to characterise strain coupling and relaxation behavior associated with magnetic/magnetoelectric phase transitions in GdMnO₃, TbMnO₃and TbMn_0.98Fe_0.02O₃through their influence on elastic/anelastic properties. Acoustic attenuation ahead of the paramagnetic to colinear-sinusoidal incommensurate antiferromagnetic transition at ∼41 K correlates with anomalies in dielectric properties and is interpreted in terms of Debye-like freezing processes. A loss peak at ∼150 K is related to a steep increase in electrical conductivity with a polaron mechanism. The activation energy,E_a, of ≳0.04 eV from a loss peak at ∼80 K is consistent with the existence of a well-defined temperature interval in which the paramagnetic structure is stabilised by local, dynamic correlations of electric and magnetic polarisation that couple with strain and have relaxation times in the vicinity of ∼10^-6s. Comparison with previously published data for Sm_0.6Y_0.4MnO₃confirms that this pattern may be typical for multiferroic orthorhombicRMnO₃perovskites (R= Gd, Tb, Dy). A frequency-dependent loss peak near 10 K observed for TbMnO₃and TbMn_0.98Fe_0.02O₃, but not for GdMnO₃, yieldedE_a⩾ ∼0.002 eV and is interpreted as freezing of some magnetoelastic component of the cycloid structure. Small anomalies in elastic properties associated with the incommensurate and cycloidal magnetic transitions confirm results from thermal expansion data that the magnetic order parameters have weak but significant coupling with strain. Even at strain magnitudes of ∼0.1-1‰, polaron-like strain effects are clearly important in defining the development and evolution of magnetoelectric properties in these materials. Strains associated with the cubic-orthorhombic transition due to the combined Jahn-Teller/octahedral tilting transition in the vicinity of 1500 K are 2-3 orders of magnitude greater. It is inevitable that ferroelastic twin walls due to this transition would have significantly different magnetoelectric properties from homogeneous domains due to magnetoelastic coupling with steep strain gradients.

Adapted Chester Step Test Can Have Maximal Response Characteristics for the Assessment of Exercise Capacity in Young Women

Chester step test (CST) estimates the exercise capacity through a submaximal response, which can limit its application in the prescription of exercise. This study aimed to assess whether an adaptation of the CST (with a progressive profile) can have maximal response characteristics in young women and compare it to the incremental shuttle walk test (ISWT). Another aim was to determine its within-day test–retest reliability. A cross-sectional study was conducted with 25 women (20.3 ± 1.5 years) who performed the field tests twice on two different days (48 h apart). The maximal effort attainment was assessed by the heart rate (HR), perception of exertion (Borg scale), and blood lactate concentration. For the performance variables, Pearson’s correlation and intraclass correlation coefficient (ICC_2,1) were used. In the best test, mean values of maximal response were observed in the adapted CST (94.0 ± 6.5% of age-predicted HR_max, 11.3 ± 4.5 mmol/dl of blood lactate, and 18.4 ± 1.5 of Borg rating). The correlations between the adapted CST and the ISWT were weak to moderate (0.38 ≤ r ≤ 0.55; p < 0.05). Fair to good reliability was found for the adapted CST (ICC_2,1 = 0.48–0.61). The adapted CST showed mean values of maximal response, weak to moderate association with the ISWT, and low within-day test–retest reliability in young women.

Measurement properties of step tests for exercise capacity in COPD: A systematic review

Objective:

To determine the level of evidence of the measurement properties (validity, reliability, and responsiveness) and interpretability of the step tests available for assessing the exercise capacity in patients with chronic obstructive pulmonary disease.

Data sources:

The data sources Web of Science, MEDLINE, PubMed, PEDro, CENTRAL of Cochrane Library, and Scopus were searched up to June 26, 2020.

Review methods:

Studies of any design that reported results for any measurement property of the step tests for assessing the exercise capacity in COPD patients were selected. One reviewer extracted the data, and two reviewers independently rated the level of evidence by using the Consensus-Based Standards for the Selection of Health Measurements Instruments recommendations.

Results:

Thirty-one studies were included in the data synthesis. Chester Step Test, Modified Incremental Step Test, two-, three-, four-, and six-Minute Step Test, Paced Step Test, and six-Minute Stepper Test were identified. A step test protocol was also found. The level of evidence of their results for the measurement properties was mostly determined as “low” to “very low.” The best level of evidence found was for the six-minute stepper test: “high” on construct validity (r = 0.56–0.71); and “moderate” on criterion validity (r = 0.36–0.69), and responsiveness (r = 0.26–0.34).

Conclusion:

The general level of evidence of the measurement properties of the step tests is “low” to “very low” for assessing exercise capacity in patients with chronic obstructive pulmonary disease, which can limit their application in clinical practice. The six-minute Stepper Test is currently the most appropriate step test available.

Effect of shock wave therapy associated with aerobic exercise on cellulite: A randomized controlled trial

BACKGROUND

Cellulite is a multifactor and controversial condition. Several methods have been explored to reduce it, not always with favorable results. Shock Wave Therapy has been shown to be effective, but the results of its association with an Aerobic Exercise Program are unknown.

AIMS

To verify whether Shock Wave Therapy in association with an Aerobic Exercise Program reduces the degree of severity of Cellulite in the gluteal region and in the ⅓ of the proximal posterior of the thigh.

METHODS

Forty-five healthy women, aged from 18 to 32, randomly assigned, considering the severity degree in the Cellulite Severity Scale and the level of physical activity, in three groups: two experimental and one control group. The control group performed the evaluations. The experimental group 1 performed an Aerobic Exercise Program, and the experimental group 2 associated this program with a Radial Shock Wave Therapy protocol. The experimental groups completed six interventions within 3 weeks. In addition, the degree of severity in the Cellulite Severity Scale, height, body composition, skin temperature, and subcutaneous adipose tissue thickness were assessed. One-way ANOVA test and Kruskal-Wallis were used to obtain the results, with level of significance of 0.05.

RESULTS

Forty-two women completed the study. There was a significant reduction in the severity of Cellulite between experimental group 2 and group 1 (P = 0.032), and from group 2 to the control group (P = 0.042).

CONCLUSION

The association of Shock Wave Therapy and Aerobic Exercise was shown to be effective in reducing the severity of cellulite.

Effect of one session of aerobic exercise associated with abdominal laser therapy in lipolytic activity, lipid profile, and inflammatory markers

BACKGROUND

Increased abdominal fat and sedentary lifestyles contribute to cardiovascular disease risk. The combination of exercise and low-level laser therapy (LLLT) appears to be an innovative method to increase the lipolytic rate of abdominal adipocytes, in order to reduce abdominal fat.

OBJECTIVES

To evaluate the effect of one session of aerobic exercise associated with abdominal laser therapy in lipolytic activity, profile lipid, and inflammatory markers (C-reactive protein-CRP).

METHODS

Experimental randomized controlled study in 36 participants of female sex divided into three groups: placebo group (PG) (n = 12), experimental group 1 (EG1) (n = 11), and experimental group 2 (EG2) (n = 13). The EG1 and EG2 performed the laser therapy protocol followed by 50 minutes of aerobic exercise on cycle ergometer, of 45%-55% of reserve heart rate; however, in EG2 the laser therapy was applied without power. The PG only performed the laser therapy protocol without power. The anthropometric measures were evaluated, and all participants were subject to blood samples at the beginning and at the end of the intervention for measure glycerol, lipid profile (total cholesterol, triglycerides, HDL, and LDL), and CRP. One-way ANOVA was used to compare the groups in the quantitative variables and Fisher's test to compare the groups in the qualitative variables. To compare the variables between moments (M0 and M1), we used the t test for paired samples.

RESULTS

In the group that performed physical exercise and lipolytic laser and in the group that performs only physical exercise, there was a significant increase in glycerol mobilization between M0 and M1 (P < .001). The same did not occur in the placebo group. Regarding the CRP levels and lipidic profile, no significant differences were observed between moments in the experimental groups.

CONCLUSION

It is concluded that one session of aerobic exercise associated with LLLT and one session of aerobic exercise appears to be able to increase the lipolytic activity. However, it appears that LLLT does not provide increased value to the aerobic physical exercise by itself in lipolysis process.

Discrimination of Benign and Malignant Lesions in Canine Mammary Tissue Samples Using Raman Spectroscopy: A Pilot Study

Breast cancer is a health problem that affects individual life quality and the family system. It is the most frequent type of cancer in women, but men are also affected. As an integrative approach, comparative oncology offers an opportunity to learn more about natural cancers in different species. Methods based on Raman spectroscopy have shown significant potential in the study of the human breast through the fingerprinting of biological tissue, which provides valuable information that can be used to identify, characterize and discriminate structures in breast tissue, in both healthy and carcinogenic environments. One of the most important applications of Raman spectroscopy in medical diagnosis is the characterization of microcalcifications, which are highly important diagnostic indicators of breast tissue diseases. Raman spectroscopy has been used to analyze the chemical composition of microcalcifications. These occur in benign and malignant lesions in the human breast, and Raman helps to discriminate microcalcifications as type I and type II according to their composition. This paper demonstrates the recent progress in understanding how this vibrational technique can discriminate through the fingerprint regions of lesions in unstained histology sections from canine mammary glands.

Investigating the anisotropic compression and high-pressure phase symmetry of orthorhombic RFeO3 vs RMnO3

Rare-earth orthoferrites and orthomanganites present strong couplings between their structural distortions and physical properties, namely magnetoelectricity, generating interest in predicting and realizing new phases under external parameters, such as hydrostatic pressure. In this regard, we discuss the differences and the similarities of the high-pressure behaviour of the structural distortions arising from anisotropic volume compression. This allows a better understanding of the role played by the octahedra tilt and Jahn-Teller effect as pressure accommodation mechanisms on the stabilization of different crystallographic phases after the insulator to metal structural transition occurring at the critical pressures (Pc) between 35 and 50 GPa.

Orthorhombic GdMnO3 Epitaxial Thin Film Grown onto SrTiO3 (110)

GdMnO3 epitaxial thin films were deposited onto (110)-oriented SrTiO3 substrates by RF magnetron sputtering. The structure, microstructure, dielectric and magnetic properties were investigated in detail. The XRD results revealed that the GdMnO3 thin films exhibit an epitaxial strained orthorhombic symmetry and grow preferably in off-plane (001) orientation, wherein the basal lattice parameters are strained by the substrate lattice. A dielectric relaxation process was ascertained, whose activation energy is sensitive to the magnetic phase transitions, occurring at 41 K and at 20 K, respectively. The canted nature of the low temperature magnetic phase is discussed.

Effect of an aerobic exercise session combined with abdominal radiofrequency on lipolytic activity in women: Randomized control trial

BACKGROUND

Abdominal adiposity is a cardiovascular risk factor; it is assumed that the combination of radiofrequency and physical exercise may decrease this excess of adipose tissue.

PURPOSE

To understand whether an aerobic physical exercise session associated with abdominal radiofrequency increases the level of lipolytic activity.

METHODOLOGY

The study analyzes the effect of a combined aerobic exercise session with radiofrequency. Participants were 30 healthy female volunteers, aged 18-28 years, randomly assigned to an experimental group and placebo group. They were characterized by a sociodemographic questionnaire, the International Physical Activity Questionnaire and the Food Frequency Questionnaire. The groups performed an abdominal radiofrequency session followed by moderate aerobic exercise, assessing glycerol concentration and lipid profile values before and after the intervention. In the experimental group, a percentage of potency was used that allowed to maintain the temperature between 40º C and 42º C to the epidermis. In the placebo group, the power of the radiofrequency was 0 Watt. To compare results, Student's t test was used for a significance level of 0.05.

RESULTS

There were no significant changes in glycerol concentrations between groups (P > 0.05). There were no changes in the lipid profile of both groups after the intervention (P > 0.05).

CONCLUSION

The association of exercise with radiofrequency did not present an increased effect on lipolytic activity when compared to the isolated exercise. The application of this technique is a safe intervention.

Effect of four sessions of aerobic exercise with abdominal radiofrequency in adipose tissue in healthy women: Randomized control trial

BACKGROUND

Abdominal adiposity is a cardiovascular risk factor; it is assumed that the combination of radiofrequency and physical exercise may decrease this excess of adipose tissue.

PURPOSE

To analyze the effect of four intervention sessions on abdominal adipose tissue.

METHODOLOGY

The study analyzes the effect of four sessions of aerobic exercise combined with radiofrequency. Participants were 28 healthy female volunteers, aged 18-28 years, randomly assigned to an experimental group and a placebo group. They were characterized by a sociodemographic questionnaire, the International Physical Activity Questionnaire and the Food Frequency Questionnaire. The groups performed four sessions of abdominal radiofrequency followed by moderate aerobic exercise, assessing body mass, body mass index, fat mass, waist circumference, waist/height ratio, subcutaneous adipose thickness, and horizontal abdominal adipose fold at the first and fourth sessions. In the experimental group, a percentage of potency was used that allowed to maintain the temperature between 40°C and 42°C to the epidermis. In the placebo group, the power of the radiofrequency was 0 W. To compare results, Student's t test was used for a significance level of 0.05.

RESULTS

There was a statistically significant decrease in waist circumference, abdominal subcutaneous adipose thickness, and horizontal abdominal fold in the experimental group compared to the placebo group (P < 0.05).

CONCLUSION

Combined exercise intervention with radiofrequency has been shown to be effective in reducing abdominal adiposity.

Tuning the Stoichiometry of Ag2S Thin Films for Resistive Switching Applications

In this work silver-rich and sulfur-rich silver sulfide (Ag2S) thin films were fabricated using a diversified set of experimental methods, namely ion beam deposition and atmosphere- and solution-based sulfurizations. The composition of the Ag2S thin films was studied using X-ray diffraction, Raman spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. We found that it strongly depends on the fabrication conditions, such as sulfurization time and temperature. These conditions, in turn, affect the electrical characteristics of the thin films, namely the resistivity and resistive switching. We were able to control the Ag2S stoichiometry and infer its dependence on the fabrication parameters for all the followed methods.